Apparatus for transferring mica onto a fibrous web



1,633,622 June 1927' J. BORER APPARATUS FOR TRANSFERRING MICA ONTO A FIBROUS WEB Filed April 19, 1926 Patented June as, 1927..

UNITED STATES J'OSEF BOBEB, O1 BREITENBAOH, NEAR IBASEL, SWITZERLAND.

APPARATUS FOR TRANSFEBRING MICA ONTO A FIBROUS WEB.

Application filed April 18,1926. Serial No. 103,144.

The present invention relates to an appa ratus for transferring mic-a onto a fibrous web, such as a paper web, with the aid of a rotating suction drum for suckin on mica flakes and giving them up to the fibrous web. In this apparatus the suction drum havin a perforated peripheral wall, is continual y rotated above a' pressure air trunk containing the mica flakes in suspension, about a stationary hollow shaft and about a stationary suction chamber within the drum in open communication with the hollow space'in said shaft, the hollow shaft being connected at both ends to a suction fan or the like, so that the mica flakes can be uniformly distributed by suction over the whole length of the circumference of the drum, in order that it may be given up on further movement of the drum to a fibrous web provided with an adhesive, in contact with the drum.

The accompanying drawing illustrates by way of example one embodiment of the present invention. 7

Fig. 1 is a vertical cross section, and

Fig. 2 is a longitudinal section thereof.

a is a suction drum ith a perforated peripheral wall, which 1s rotatable about a fixed horizontal hollow shaft 1). Within the drum a a sector like shaped suction chamber d is divided off by two stationary radial walls 0, 0 which are firmly secured to the shaft 6, the drum a being so rotated that its peripheral wall passes outside the chamber d. The suction chamber d is in communication with the hollow space inside the shaft 6 through alongitudinal slot b 'thereof,

The suction chamber divided off within the drum (1 is located above a vertical trunk e which can be supplied with mica which is whirled and held in suspension therein by pressure air supplied by a pressure blower t at the lower end of the trunk.

The hollow shaft 12 is connected at the ends with suction fans f, 7. The suction in the chamber d is thus distributed uniformly over the whole length of the drum, by the said suction fans, so that the suction acts with the same strength over the whole circumference of the drum, which could not be I,

low shaft carrying sald drum, means to rethe case if only one ventilator were provided,

since then owing to the one sided suction stream, the suction action at the drum circumference would be stronger at one end, this causing the deposition of an uneven layer of mica at the drum circumference.

The mica is, here however, deposited by the suction stream in a uniform layer over the whole length of the drum at the part of the drum covering within the suction area. To ensure this distributed action, guiding wings 9, adjustable if necessary, can be provided in the suction chamber d.

The mica adhering to the drum covering through the suction comes during the further course of movement of the drum into reach of a fibrous web h, arriving from a supply roller i and provided with an adhesive, andwvhich after passing over a guide roller 7:, touches the rotating suction drum at a place where it runs over a heated pres-- sure roller m, in order to take up the mica layer now out of the range of influence of the suction chamber (2, from the drum covering by the adhesive softened by the heated roller m and so become coated with m'ica.

Packlng members 0, p ensure a tight joint with the drum at the upper end of the trunk e.

The drum a can be driven by means of a toothed wheel (1 Its covering is kept clean by a roller brush 8 outside the working range.

What I claim is:

1. An apparatus for transferring mica onto a fibrous web, comprising a. mica supplied trunk, means to keep mica flakes therein in suspension, a rotary perforated drum arranged above said trunk, a stationary hollow shaft carrying said drum, means to rotate said drum around this shaft, a stationary suction chamber within said drum, arranged to communicate with the hollow space of the shaft and to draw up the mica flakes against the periphery of the drum, suction means connected to both ends of said shaft, and a heated pressure roller in contact with the drum outside the suction area to press a fibrous web coated with an adhesive against the drum for receiving the mica layer supplied by the drum.

2. An apparatus for transferring mica onto a fibrous web, comprising a mica suplied trunk, means to keep mica flakes therein in suspension, a rotary perforated drum arranged above said trunk, a stationary holtate said drum around this shaft, a stationary suction chamber within said drum, ar ranged to communicate with the hollow space of the shaft and to draw up the mica flakes against the periphery of the drum,

suction means connected to both ends of said shaft, guiding wings within said suction chamber to ensure distribution of the suction action of said means therein, and a heated pressure roller in contact with the drum outside the suction area to press a fibrous web coated with an adhesive against the drum for receiving the mica layer supplied by the drum.

3. An apparatus for transferring mica onto a fibrous web, comprising a mica sup.- plied trunk, a pressure air supplying device at the lower end of said trunk to keep mica flakes therein in suspension, a rotary perfo- 15 rated drum arranged above said trunk, a.

stationary hollow shaft carrying said drum,

means to rotate said drum around this shaft a stationary suction chamber within said drum, arranged to communicate with .the

hollow space of the shaft and to draw up 20 press a fibrous web coated with an adhesive 25 against the drum for receiving the mica layer supplied by the drum.

In witness whereof I have hereunto signed my name this 8th :day of A ril 1926.

J 0 EF BORER. 

